INDIANAPOLIS — Agronomists and crop specialists with certain agricultural companies are touting very narrow rows with high seeding rates as key to higher corn yields.

While 30-inch rows are considered average in most parts of the U.S. and 20-inch rows are considered narrow, Stine Seed Co. agronomists are taking row spacing to a new level with 12-inch corn rows.

This shift toward narrower rows is not merely a trend, but a clue about where production agriculture is moving, said a Stine Seed regional sales agronomist.

“We feel the big yield increases in corn will come from 12-inch-rows with equidistant spacing to increase populations, and we’re developing hybrids that withstand populations,” said Bill Kessinger of Stine Seed, for which he works in central and northern Indiana and Ohio.

Stine Seed planted 2,500 acres in 12-inch rows in central Iowa in 2012 — the first experiment of its kind to test the company’s new corn hybrids developed for high populations, along with additional trials at the company’s bioresearch station, using 60-foot John Deere and Great Plains planters.

To handle harvest, they built two 12-inch-row corn heads — one 20-foot and one 30-foot — on a Stine Seed farm outside Adel, Iowa, using the narrow-row corn head built by Illinoisan Marion Calmer for the company, equipped with redesigned gear boxes and a single gathering chain.

Stine Seed converted equipment to the latest low-pressure agricultural tires, which allow equipment to cover fields without damaging young plants or compacting soil.

Kessinger said that while every row width is possible, 12-inch rows are ideal because they are the narrowest selection to get a uniform growth platform with farm machinery.

Farmers can achieve great equidistant spacing by planting their corn 12 inches apart in rows at a rate of 43,560 plants per acre, which amounts to an acre of corn, Kessinger said.

“You can’t get equidistance with 30-inch rows,” he said. “Emergence is key. You’ve got to have good seed-to-soil contact and good depth control.”

For much of modern production agriculture, farmers have been moving toward planting higher corn populations while narrowing their row widths, he noted.

The agronomist said the development of hybrids with shorter plant heights and more upright leaf structures will allow them to better intermingle and use sunlight.

In a drought year, increased populations have led to lower canopy temperatures and shorter plant heights, which require less maintenance, he said.

Farmers who push their plant populations to high points will, in turn, increase their drought tolerance because they are keeping temperatures within the canopy, he said.

“The ground already is a little cooler and the canopy is a lot denser, keeping moisture trapped within the canopy,” he said. “If it does rain, more plants take up moisture more quickly because you’re maintaining a smaller plant.”

Kessinger said that farmers have progressively narrowed their rows with the advancement of farm equipment technology and that the only thing slowing them down presently is genetics.

“All our corn seed production is grown in 22-inch rows, and all field corn is grown in 22-inch rows,” he said. “Everything is on a narrower row and higher population.”

The agronomist said the company would test higher populations every year, since some farmers plant their corn seed at a rate of 33,000 seeds per acre and some at higher numbers.

With increased population comes increased management, and narrower rows could mean higher insect pressure, he said.

Kessinger added that since it takes seven years to breed a corn plant, breeders must try to foresee where the industry will be seven years down the road.

Stine Seed began testing corn trials on narrower rows about seven years ago, and though the data is just starting to emerge, he insisted that narrower row spacing is not just a trend.

He said the company currently is building two smaller units for 12-inch rows so farmers in Indiana and other parts of the country can participate in the trials.

“I think farmers are going to go to higher populations and narrower rows — the machinery companies are building more narrow row units,” he said. “The technology will be there. We’re really pushing for the right genetics to be developed, though I don’t think we’ll do it on genetics alone.”

He said the narrower rows will require the development of more durable genetic breeds of corn that can handle the stress of higher seed populations.

The seed company planted most of its trials using the 9733 hybrid in a conventional tillage system, he said.

“There still is a lot we could do with 30-inch rows — a lot of guys on 20s can push it even higher,” the agronomist noted. “Right now, a lot of farmers are planting in the 32,000 to 34,000 range, but I think they can easily go to 36,000 and 39,000.”